Supercritical Hydrogen Adsorptivity of Amorphous Carbon Mesotubes

Abstract

High-pressure adsorption isotherms of hydrogen onto amorphous carbon mesotubes (ACMs) prepared from fluorine polymer and onto activated carbon fibres (ACFs) were measured at temperatures of 77, 196 and 303 K, respectively, at pressures up to 10 MPa. The adsorption isotherms for ACMs and ACFs at 77 K exhibited maxima at 1 MPa (8.0 wt%) and 4 MPa (3.7 wt%), respectively, although both isotherms at 303 K were of the Henry type and both amounts of hydrogen adsorbed at 8 MPa were less than 0.3 wt%. The maximum hydrogen adsorption amount for ACMs per unit micropore volume as determined by N 2 adsorption was 10-times larger than that for ACFs. ACMs are different from ACFs in that they are thought to have specific ultramicropores, although characterization using high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy showed that they possessed a nanographitic structure similar to that of ACFs.

Poly(vinylidene chloride)-Based Carbon with Ultrahigh Microporosity and Outstanding Performance for CH4 and H2 Storage and CO2 Capture

“…It is very obvious that adsorption trend for H 2 uptake is proportional to the surface area of carbons. Although H 2 storage uptake of 4.85 wt % for AC4-PC is still at a relatively inferior situation compared to some previous reported data on zeolite-templated carbons and carbon mesotubes, ,− the reported value is larger than most other kind of activated carbons. , It is true that a recent evaluation of H 2 uptake over a wide range of high surface area activated carbons has observed a maximum uptake of 4.5 wt % even at much higher pressures . On the other hand, H 2 uptake at -196 °C and 1 bar for AC4-PC in Figure b is exceptionally up to 2.43 wt %, which is among the largest uptake reported in literatures for any adsorbents, to the best of our knowledge.…”